Preparation of 21-acyloxy allopregnanes



Patented May 13, 1952 PREPARATION OF ZI-ACYLOXY ALLOPREGNAN ES Stephen Kaufmann, George Rosenkranz, and John Pataki, Mexico City, Mexico, assignors to Syntex S. A., Mexico City, Mexico, a corporation of Mexico- No Drawing. Application January 23, 1950, Serial No. 140,151'

8 Claims.

The present invention relates toa process for preparing cyclopentanophenanthrene derivatives.

More particularly the present invention relates to a process for the production of 17a-hydroxy- 20-keto-2l-acyloxy allopregnane derivatives.

The introduction of the 2l-acetoxy-group into iT-hydroxyallopregnane compounds represents a diflicultproblem. In fact, I. Salamon and T. Reichstein (Helv. Chim. Acta 30, 1619 (1947)) attempted unsuccessfully to convert the bromine atom into an acetoxy group in 2l-bromoallopregmane-3,6,17B-dil-20-one 3,17-diacetate by reacting the latter with alkali or silver acetate.

In accordance with the present invention, the surprising discovery has been made, however, that the conversion of the 2l-halogen atom into an acetoxy group takes place very smoothly when the l7-hydroxy group is in the a position. In accordance with the present invention, therefore, it was found that the halogen atom in the 21-position could be converted into the 2l-acetoxy group in compounds of the following general formula:

Cl-lihalogcn O C Ha L--- OH In the above formula X is selected from the group consisting of 0:0, CH2,

H H c c v were added 40 grams of potassium acetate.

reaction preferably takes place upon heatingor refluxing the bromo compound with the alkali metal lower fatty acid salt. Typical alkali metal lower fatty acid salts for the reaction are potassium or sodium acetate, potassium or sodium propionate, etc. The allopregnane compounds, which are thus reacted, may be otherwise substituted or unsubstituted in the ring system, for example, substituents in the ring system may consist of hydrox-yl, alkoxyl, acyloxyl or keto groups, or the corresponding thio derivatives and other ether groups. The zl-halogen derivatives, which are the starting materials-for the present invention, may be readily produced by brominating the corresponding allopregnane compound in a conventional manner. Thereafter the corresponding iodo derivative, for example, may be prepared by reacting the 21-bromo compound with an alkali metal iodide, such as sodium iodide.

The following specific examples serve to illustrate the present invention but ar not intended to limit the same:

Example I To a solution of 5 grams of 2l-bromoal1opregnane-3B,17a-diol-20-one 3-acetate (Reichsteins substance L conventionally esterified in the 3-position and conventionally brominated in the 21- position) in 200 cc. of acetone were added 20 grams of potassium acetate. The mixture was refluxed for 6 hours, concentrated and poured into water. The precipitate was filtered, washed thoroughly with water and dried. After recrystallization first from chloroform-methanol and then from benzene, the allopregnane- 313,17a,21 triol 20 one 3,2l-diacetate (Reichsteins substance P) melted at 208 to 210 C.

Example II To a solution of 5 grams of 21-bromoa1lopregnane-3p,17a-diol-20-one 3-acetate in 200 cc. of acetone were added 2.5 grams of sodium iodide dissolved in cc. of acetone. After refluxing for 15 minutes the preciptated sodium bromide was filtered and the filtrate containing the 21- iodo derivative was refluxed with 20 grams of potassium acetate for 5 hours. The reaction mixture was worked up in the same manner as in Example I, whereby pure allopregnane-3/3,17a-21- triol-20-one 3,2l-diacetate with melting point 208 to 210 C. was obtained.

Example III To a solution of 10 grams of 21-bromoallopregnane-3fi,17a-diol-20-one in 600 cc. of acetone The Example IV To a solution of 5 grams of 21-bromoallopregnane-17a-0l-3,20-dione (prepared by conventionally brominating in the 21-position allopregnane- 17a-01-3,20-di0118, prepared in accordance with V the application of George Rosenkranz, Stephen Kaufmann and John Pataki, Serial No. 116,624, filed September 19, 1949) in 500 cc. of acetone are added 20 grams of potassium acetate. The re- 7 action mixture is refluxed for 6 hours, concentrated and poured into water. The precipitate is crystallized from ethyl acetate giving pure allopregnane-17a,21-dio1-3,20 dione 2l-acetate of melting point 244 to 247 C.

It will be obvious to those skilled in the art that various changes may be made Without departing from the spirit of the invention and therefore the invention is not limited to What is described in the specification but only as indicated in the appended claims.

We claim:

1. A method for producing l7-hydroxy-20- keto-21-acyloxyl allopregnane compounds, which comprises reacting 2l-halogen-l7a-hydroxy1-20- keto allopregnane compounds with an alkali metal salt of a lower fatty acid in an organic solvent for the 21-halogen-17a-hydroxy-20-keto allopregnane compounds.

2. A method for producing allopregnane- 3 8,17a,21-triol-20-one 3,21-diacetate, comprising reacting 21-halogen-allopregnane-35,l7a-diol-20- one 3-acetate with an alkali metal acetate in an organic solvent for said 21-halogen-allopregnane- 3p,17a-diol-20-one 3-acetate.

3. A method for producing allopregnane- 3B,17a,21-triol-20-one 3,21-diacetate, comprising reacting 21 bromoall0pregnane-3B,l7a-diol-2O- one 3-acetate with an alkali metal acetate in an acting organic solvent for said 21-bromoa1lopregnane- 3p,17a-diol-20-one 3-acetate.

4. A method for producing allopregnane- 3p,17a,21-triol-20-one 3,21-diacetate, comprising reacting 2l-iodo allopregnane-3p,17a-diol-20-one B-acetate with an alkali metal acetate in an organic solvent for said 21-iodoal1opregnane- 3fi,17a-di01-20-0I18 3 acetate.

5. A method for producing allopregnane- 3p3,17a,21-triol-20-one 2l-acetate comprising reacting 2l-halogen-allopregnane-35,17a-di0l-20- one with an alkali metal acetate in an organic solvent.

6. A method for producing allopregnane- 3,9,17a,21-triol-20-one 21-acetate, comprising reacting 2l-bromoallopregnane, 3B,17a-diol-20-one with an alkali metal acetate in an organic solvent for said 21-bromoallopregnane, 3,3,17a-di01- 20-one.

7. A method for producing allopregnane- 17,21-diol-3,20-dione 21-acetate comprising reacting 21-halogen-allopregnane-17a,ol-3,20-dione with an alkali metal acetate in an organic solvent for said 21-halogen-allopregnane-17a,01-

3,20 -dione.

8. A method for producing allopregnane- 17a,21-C1iO1-3,20-di01'16 21-acetate, comprising re- 2l-bromoallopregnane-17a-ol-3,20-dione with an alkali metal acetate in an organic solvent for said 2l-bromoal1opregnane-17 -ol-3,20-dione.

STEPHEN KAUFMANN. GEORGE ROSENKRANZ. JOHN PATAKI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,232,730 Reichstein Feb. 25, 1941 2,359,772 Marker Oct. 10, 1944 2,409,043 Inhoflzen Oct. 8, 1946 2,423,517 Reichstein July 8, 1947 

1. A METHOD FOR PRODUCING 17-HYDROXY-20KETO-21-ACYLOXYL ALLOPREGNANE COMPOUNDS, WHICH COMPRISES REACTING 21-HALOGEN-17A-HYDROXYL-20 KETO ALLOPREGNANE COMPOUNDS WITH AN ALKALI METAL SALT OF A LOWER FATTY ACID IN AN ORGANIC SOLVENT FOR THE 21-HALOGEN-17A-HYDROXY-20-KETO ALLOPREGNANE COMPOUNDS. 